How to configure a Formula field

To add a formula field to your form,

1. Click the Formula  field under the Form Fields section in the left pane of the form builder.
   
2. In the pop-up, your form fields would appear in the left pane. Use the fields on the left, numbers, and mathematical operators on the right to come up with your formula.
   
   
   
3. Click Done.
   
4. You can choose to hide this field from your respondents using the   Hide Field  option under  Properties . 
   
5. If you wish to edit your formula, click the Edit  link under Properties.
   

Note : 

While using the Formula field as a variable for calculating another formula, ensure that the two formulas are not mutually dependent. If you have come across an error because two formulas are mutually dependent, then refer to the below example:

If  n1, n2, n3 are three number fields, and f1, f2, f3 are the formulas that you have created where,

f1= n1+ n2 
f2= n3 + f3
f3= f1 + f2

Formula 2 depends on Formula 3's answer (and vice versa) to perform calculations, resulting in an endless loop. Recheck your formula to avoid this type of infinite loop.

Functions

1. Tap on the math function you wish to add.
   
2. It generates a syntax like this:  Function (Field Name - Field Name) .
   
3. Replace the field's placeholders with the required form fields by clicking them from the left pane. 
   
   
   

Adding a Unit to Formula